Vacuum insulating glass (VIG) units typically include two spaced apart glass substrates with an evacuated or low-pressure gap/space/cavity therebetween. The substrates are interconnected by a peripheral edge seal, which is located proximate a peripheral edge of the unit. VIG window units may include an array of spacers/pillars between the glass substrates to maintain spacing between the glass substrates and to avoid collapse of the glass substrates that may be caused due to the low pressure environment that exists between the substrates. Some example VIG window units are disclosed, for example, in U.S. Pat. Nos. 5,657,607, 5,664,395, 5,657,607, 5,902,652, 6,701,749 and 6,383,580, the disclosures of which are all hereby incorporated by reference herein in their entireties.
FIGS. 1 and 2 illustrate an example VIG window unit 1. For example, VIG unit 1 may include two spaced apart substantially parallel glass substrates 2, 3, which enclose an evacuated low-pressure space/cavity 6 therebetween. Glass sheets or substrates 2, 3 are interconnected by a peripheral edge seal 4 which may be made of fused solder glass or the like, for example. An array of support pillars/spacers 5 may be included between the glass substrates 2, 3 to maintain the spacing of substrates 2, 3 of the VIG unit 1 in view of the low-pressure space/gap 6 present between the substrates 2, 3. A coating such as a low-E coating (not shown) may be located on an interior surface of substrate 2 or substrate 3.
A pump-out tube 8 may be hermetically sealed by, for example, solder glass 9 or the like to an aperture/hole 10 that passes from an interior surface of one of the glass substrates 2 to the bottom of an optional recess 11 in the exterior surface of the glass substrate 2, or optionally to the exterior surface of the glass substrate 2. A vacuum is attached to and/or communicates with pump-out tube 8 to evacuate the interior cavity 6 to a low pressure that is less than atmospheric pressure, for example, using a sequential pump down operation. After evacuation of the cavity 6, a portion (e.g., the tip) of the tube 8 is melted to seal the vacuum in low pressure cavity/space 6. The optional recess 11 may retain the sealed pump-out tube 8. Optionally, a chemical getter 12 may be included within a recess 13 that is disposed in an interior face of one of the glass substrates, e.g., glass substrate 2. The chemical getter 12 may be used to absorb and/or bind with certain residual impurities that may remain after the cavity 6 is evacuated and sealed.
VIG units with peripheral edge seals 4 may be manufactured by depositing glass frit or other suitable material, in a solution (e.g., frit paste), around the periphery of substrate 2 (or on substrate 3). This glass frit paste ultimately forms the edge seal 4. The other substrate (e.g., 3) is brought down on substrate 2 so as to sandwich spacers/pillars 5 and the glass frit solution between the two substrates 2, 3. The entire assembly including the glass substrates 2, 3 and the seal material (e.g., glass frit in solution or paste) is then heated to a temperature at which point the glass frit melts, wets the surfaces of the glass substrates 2, 3, and ultimately forms a hermetic peripheral/edge seal 4.
After formation of the edge seal 4 between the substrates, a vacuum is drawn via the pump-out tube 8 to evacuate cavity 6 and thus form low pressure space/cavity 6 between the substrates 2, 3. The pressure in cavity/space 6 may be produced by way of an evacuation process to a level below atmospheric pressure, e.g., below about 10−2 Torr. To maintain the low pressure in the space/cavity 6, substrates 2, 3 are hermetically sealed via the edge seal 4 and sealing off of the pump-out tube. Small high strength spacers/pillars 5 are provided between the transparent glass substrates to maintain separation of the approximately parallel glass substrates against atmospheric pressure. As noted above, once the space 6 between substrates 2, 3 is evacuated, the pump-out tube 8 may be sealed, for example, by melting its tip using a laser or the like.
Dual pane VIG window units are generally much more efficient insulators than dual pane non-vacuum IG window units. VIG window units, while having better performance, are also significantly thinner than non-vacuum IG window units and thus can be advantageous with respect to reduced weight and/or aesthetics. It will be appreciated that standard non-vacuum IG window units are rather thick, and come in various thicknesses (e.g., from about 19-40 mm thick). On the other hand, VIG window units are often significantly thinner (e.g., from about 4-12 mm thick, more preferably from about 4-10 mm thick, more preferably from about 7-9 mm thick, with an example thickness being about 8.3 mm) than typical non-vacuum IG window units. And thermal performance of VIG units is dramatically better than that of non-vacuum IG window units (e.g., VIG units have higher R-values than do nonvacuum IG units).
A related art IG window unit, which is not a vacuum IG unit, is shown in FIG. 3 and includes a window frame surrounding a nonvacuum IG window unit. FIG. 3 illustrates nonvacuum IG window unit 30, which may include two panes of glass 36 defining an air or gas-filled gap 38 therebetween. The gap 38 is at atmospheric pressure, so it is not a vacuum window unit. The IG window unit 30 is shown seated in/on a window sash 32. The gap 38 between the glass substrates 36 is typically air and/or gas filled, and is at approximately atmospheric pressure (unlike a VIG window unit), and the interior space/gap 38 is sealed via peripheral spacer system 29. The vinyl sash 32 may include a first stop portion 35 that is part of and integral with main sash portion 32, a second removable stop 34 that may include a clip or other extending portion 37 for connecting the second stop 34 to the main sash portion 32 via a recess 32a. Voids/cavities defined in the sash 32 and/or stop 34 are filled with either air at atmospheric pressure or with expandable foam 31. Stops 34 and 35 may or may not be integral with main sash portion 32 which is provided under and/or adjacent the outer edge of the window unit. Stops 34 and 35 may be substantially parallel to each other. The IG window unit is held and/or positioned, directly or indirectly, between the stops 34, 35. When the IG unit 30 is seated in/on the sash portion 32 and is engaged with the first stop portion 35, the second stop 34 is connected to the sash 32, for example, via the clip or extended portion 37. The stops 34, 35 provide lateral support to the IG window unit 30. The sash 32 and stop portions 34, 35 may be made of material such as vinyl and/or PVC.
While the window frame of FIG. 3 is excellent for its intended purpose of insulating nonvacuum IG window units, the window frame shown in FIG. 3 is insufficient for adequately insulating the periphery of VIG window units. An example VIG window unit provides a COG efficiency of about R12. A VIG window unit, like an IG window unit, is to be mounted in a window frame which surrounds the VIG window unit. Conventional window frames include numerous voids which can be filled with insulating expandable foam (e.g., see foam 31 in FIG. 3) for increasing the insulating value of the frame. Unfortunately, the structure of conventional window frames reduces the overall performance of VIG window units because conventional window frames such as that shown in FIG. 3 do not sufficiently insulate the periphery of VIG window units. This is largely because of space constraints of the window design and insulative materials 31 utilized within such frames. Conventional window frames do not adequately insulate the periphery of VIG units to sufficiently reduce conduction through the glass/seal and/or through the frame itself. Typical insulating expandable foam 31, which is placed in frame voids/cavities as shown in FIG. 3, obtains an R5-R6 per inch of thickness. Thus, to obtain R-values approaching that of the VIG unit, the frame would be required to incorporate extremely thick foam segments in order to effectively insulate the perimeter of the VIG window unit.
Thus, it will be appreciated that there exists a need in the art for more effective window frames that can more efficiently and/or effectively insulate the perimeter of VIG window units.
In certain example embodiments of this invention, there is provided a window that includes a VIG window unit in a window frame. The frame includes at least one vacuum insulated structure (VIS) for improving the insulating characteristics of the frame, so that the frame can adequately insulate the periphery of the VIG unit. Such windows, including both the VIG window unit and the frame which includes at least one VIS, may be used in residential and/or commercial window applications for buildings and the like. The use of a window frame having at least one VIS is advantageous in that it allows for improved window frame thermal performance and a narrow frame design for improved aesthetics.
In certain example embodiments of this invention, there is provided a window comprising: a vacuum insulated glass (VIG) window unit in a window frame; said VIG window unit comprising first and second glass substrates with a low pressure gap provided therebetween, the low pressure gap being at pressure less than atmospheric pressure; said window frame comprising a plurality of elongated cavities; and a vacuum insulated structure located in at least one of said elongated cavities of said window frame, said vacuum insulated structure comprising a sealed flexible envelope that encases insulating material, and wherein an interior of said sealed flexible envelope is at a pressure less than atmospheric pressure.
In certain example embodiments of this invention, there is provided a window frame for use in a window including a vacuum insulated glass (VIG) window unit, said VIG window unit comprising first and second glass substrates with a low pressure gap provided therebetween, the low pressure gap being at pressure less than atmospheric pressure, the window frame comprising: a plurality of elongated cavities for extending along an edge portion of the window; and a vacuum insulated structure located in at least one of said elongated cavities, said vacuum insulated structure including a sealed envelope that encases insulating material, and wherein an interior of said sealed envelope is at a pressure less than atmospheric pressure.
In certain example embodiments of this invention, there is provided a window frame for use in a window including a window unit, said window unit comprising first and second glass substrates with a gap provided therebetween, the window frame comprising: a plurality of elongated cavities for extending along an edge portion of the window; and a vacuum insulated structure located in at least one of said elongated cavities, said vacuum insulated structure including a sealed envelope that encases insulating material, and wherein an interior of said sealed envelope is at a pressure less than atmospheric pressure.
These and other embodiments and/or advantages are described herein with respect to certain example embodiments and with reference to the following drawings in which like reference numerals refer to like elements throughout the several views, wherein: